:root {
  --bg: #f5f5f2;
  --panel: #ffffff;
  --text: #1c1c1a;
  --muted: #5d5d58;
  --line: #d6d6d0;
  --accent: #1f5fbf;
  --accent-text: #ffffff;
  --code-bg: #fbfbf9;
  --gutter-bg: #eeeeea;
  --hl: #fff2c2;
  --bp: #c62828;
  --err-bg: #fde8e6;
  --err-text: #8f1d14;
  --ok-text: #1b6b34;
  --chg: #b45309;
  --font: -apple-system, "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #161615;
    --panel: #1f1f1d;
    --text: #ececE8;
    --muted: #a3a39c;
    --line: #3a3a36;
    --accent: #6ea8ff;
    --accent-text: #0b1a33;
    --code-bg: #181817;
    --gutter-bg: #262624;
    --hl: #4a4020;
    --bp: #ff6b63;
    --err-bg: #3b1f1c;
    --err-text: #ffb4ab;
    --ok-text: #7fd39a;
    --chg: #f0a35a;
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.6 var(--font);
}
.wrap { width: 100%; max-width: 1280px; margin: 0 auto; padding: 0 16px; }
a { color: var(--accent); }
code, pre, kbd { font-family: var(--mono); }
code { font-size: 0.92em; background: var(--gutter-bg); padding: 0 4px; border-radius: 3px; }

.banner { background: var(--err-bg); color: var(--err-text); padding: 10px 16px; }

.top { border-bottom: 1px solid var(--line); background: var(--panel); }
.top .wrap { padding-top: 14px; padding-bottom: 12px; }
.top h1 { margin: 0; font-size: 20px; line-height: 1.3; }
.top p { margin: 2px 0 0; color: var(--muted); font-size: 14px; }

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  padding-top: 16px;
  padding-bottom: 24px;
}
#pane-screen { order: 1; }
#pane-editor { order: 2; }
#pane-debug { order: 3; }
#pane-quirks { order: 4; }
@media (min-width: 960px) {
  .layout {
    grid-template-columns: minmax(0, 1fr) minmax(0, 560px);
    grid-template-areas: "editor screen" "debug quirks";
    align-items: start;
  }
  #pane-screen { grid-area: screen; }
  #pane-editor { grid-area: editor; }
  #pane-debug { grid-area: debug; }
  #pane-quirks { grid-area: quirks; }
}

.pane { background: var(--panel); border: 1px solid var(--line); border-radius: 8px; padding: 14px 16px 16px; min-width: 0; }
.pane h2 { margin: 0 0 10px; font-size: 16px; }
.pane h3 { margin: 14px 0 6px; font-size: 13px; color: var(--muted); font-weight: 600; }
.hint { margin: 6px 0; color: var(--muted); font-size: 13px; }

button, select, input[type="text"], .filebtn {
  font: inherit;
  color: var(--text);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 6px 12px;
  min-height: 38px;
}
button, .filebtn { cursor: pointer; }
button:hover:not(:disabled), .filebtn:hover { border-color: var(--muted); }
button:disabled { opacity: 0.5; cursor: default; }
button.primary { background: var(--accent); color: var(--accent-text); border-color: var(--accent); font-weight: 600; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.filebtn { display: inline-flex; align-items: center; position: relative; }
.filebtn input { position: absolute; inset: 0; opacity: 0; cursor: pointer; width: 100%; }
.filebtn:focus-within { outline: 2px solid var(--accent); outline-offset: 2px; }

.row { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.field { display: inline-flex; align-items: center; gap: 6px; font-size: 14px; }
.field.grow { flex: 1 1 220px; }
.field.small input[type="color"] { width: 38px; height: 34px; padding: 2px; border: 1px solid var(--line); border-radius: 6px; background: var(--panel); }
.check { display: inline-flex; align-items: center; gap: 6px; font-size: 14px; min-height: 38px; }
.check input { width: 18px; height: 18px; }
.range { display: inline-flex; align-items: center; gap: 8px; flex: 1; min-width: 0; }
.range input { flex: 1; min-width: 80px; }
.range output { min-width: 3.2em; text-align: right; font-family: var(--mono); }
.unit { color: var(--muted); font-size: 13px; }
.settings { margin-top: 10px; }

/* 畫面 */
.stage { background: var(--gutter-bg); padding: 0; border-radius: 6px; overflow: hidden; }
#screen {
  display: block;
  width: 100%;
  aspect-ratio: 2 / 1;
  height: auto;
  image-rendering: pixelated;
  image-rendering: crisp-edges;
  image-rendering: pixelated;
  border-radius: 6px;
}
#screen:focus-visible { outline-offset: -2px; }
.status { margin: 8px 0; min-height: 1.6em; font-size: 14px; color: var(--muted); }
.controls { margin-top: 4px; }

.keypad {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
  margin-top: 14px;
  max-width: 360px;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}
.keypad button {
  min-height: 56px;
  font-family: var(--mono);
  font-size: 20px;
  font-weight: 600;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  line-height: 1.1;
  padding: 4px;
  touch-action: none;
  -webkit-touch-callout: none;
}
.keypad button small { font-size: 11px; font-weight: 400; color: var(--muted); }
.keypad button.down { background: var(--accent); color: var(--accent-text); border-color: var(--accent); }
.keypad button.down small { color: var(--accent-text); }

/* 編輯器 */
.toolbar { margin-bottom: 4px; }
.editor {
  display: flex;
  height: 460px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--code-bg);
  overflow: hidden;
  font: 13px/20px var(--mono);
}
.gutter {
  flex: none;
  width: 52px;
  overflow: hidden;
  background: var(--gutter-bg);
  border-right: 1px solid var(--line);
  padding: 8px 0 24px;
  color: var(--muted);
  user-select: none;
  -webkit-user-select: none;
}
.gutter .ln {
  height: 20px;
  padding: 0 8px 0 18px;
  text-align: right;
  cursor: pointer;
  position: relative;
}
.gutter .ln:hover { background: var(--line); }
.gutter .ln.bp::before {
  content: "";
  position: absolute; left: 5px; top: 5px;
  width: 10px; height: 10px; border-radius: 50%;
  background: var(--bp);
}
.gutter .ln.err { color: var(--err-text); background: var(--err-bg); font-weight: 700; }
.gutter .ln.cur { color: var(--text); font-weight: 700; }
.scroller { position: relative; flex: 1; min-width: 0; overflow: hidden; }
.hl { position: absolute; left: 0; right: 0; height: 20px; background: var(--hl); pointer-events: none; }
#src {
  position: relative;
  display: block;
  width: 100%; height: 100%;
  margin: 0;
  padding: 8px 10px 8px 10px;
  border: 0; border-radius: 0;
  background: transparent;
  color: var(--text);
  font: inherit;
  line-height: 20px;
  white-space: pre;
  overflow: auto;
  resize: none;
  tab-size: 4;
  min-height: 0;
}
#src:focus { outline: none; }
.editor:focus-within { outline: 2px solid var(--accent); outline-offset: 1px; }

.messages { margin-top: 8px; font-size: 14px; }
.messages .ok { color: var(--ok-text); margin: 0; }
.messages ul { list-style: none; margin: 0; padding: 0; }
.messages li + li { margin-top: 4px; }
.messages button {
  width: 100%; text-align: left; background: var(--err-bg); color: var(--err-text);
  border-color: transparent; min-height: 34px; padding: 4px 10px;
}
.messages .warn { color: var(--chg); margin: 4px 0 0; }

.help { margin-top: 12px; border-top: 1px solid var(--line); padding-top: 10px; }
.help summary { cursor: pointer; font-weight: 600; }
.help pre {
  background: var(--code-bg); border: 1px solid var(--line); border-radius: 6px;
  padding: 10px 12px; overflow-x: auto; font-size: 12.5px; line-height: 1.55;
}
.help table { width: 100%; border-collapse: collapse; font-size: 13px; }
.help th, .help td { text-align: left; padding: 5px 8px 5px 0; border-bottom: 1px solid var(--line); vertical-align: top; }
.help th { color: var(--muted); font-weight: 600; }
.help td code { display: inline-block; margin: 1px 2px 1px 0; }

/* 除錯 */
.debug-grid { display: grid; grid-template-columns: minmax(0, 1fr); gap: 0 20px; }
@media (min-width: 560px) { .debug-grid { grid-template-columns: minmax(0, 1fr) 150px; } }
.regs { display: grid; grid-template-columns: repeat(4, 1fr); gap: 4px; font-family: var(--mono); font-size: 13px; }
.regs div { border: 1px solid var(--line); border-radius: 4px; padding: 3px 6px; display: flex; justify-content: space-between; gap: 6px; }
.regs div b { font-weight: 600; color: var(--muted); }
.regs div.chg { border-color: var(--chg); color: var(--chg); font-weight: 700; }
.specials { display: grid; grid-template-columns: repeat(4, 1fr); gap: 4px; margin: 8px 0 0; font-family: var(--mono); font-size: 13px; }
.specials div { border: 1px solid var(--line); border-radius: 4px; padding: 3px 6px; display: flex; justify-content: space-between; gap: 6px; }
.specials dt { color: var(--muted); font-weight: 600; }
.specials dd { margin: 0; }
.specials .chg { border-color: var(--chg); color: var(--chg); font-weight: 700; }
.stack { list-style: none; margin: 0; padding: 0; font: 12.5px/1.5 var(--mono); columns: 2; column-gap: 8px; }
.stack li { color: var(--muted); padding: 0 4px; border-radius: 3px; }
.stack li.used { color: var(--text); }
.stack li.top { background: var(--hl); color: var(--text); font-weight: 700; }
@media (min-width: 560px) { .stack { columns: 1; } }

.disasm { list-style: none; margin: 0; padding: 0; font: 13px/1.6 var(--mono); border: 1px solid var(--line); border-radius: 6px; overflow: hidden; }
.disasm li { display: flex; gap: 12px; padding: 0 10px; white-space: pre; overflow-x: auto; }
.disasm li.pc { background: var(--hl); font-weight: 700; }
.disasm li.bp::before { content: ""; width: 8px; height: 8px; margin-top: 8px; border-radius: 50%; background: var(--bp); flex: none; }
.disasm .a { color: var(--muted); min-width: 4.5em; }
.disasm .h { color: var(--muted); min-width: 3.6em; }

.mem-bar { margin-bottom: 6px; }
.mem {
  margin: 0; padding: 8px 10px; border: 1px solid var(--line); border-radius: 6px;
  background: var(--code-bg); font-size: 12px; line-height: 1.5; overflow-x: auto; max-height: 300px; overflow-y: auto;
}
.mem .pcb { background: var(--hl); font-weight: 700; }
.mem .ib { outline: 1px solid var(--accent); }
.mem .addr { color: var(--muted); }

/* quirks */
.quirks { margin-top: 10px; display: grid; gap: 10px; }
.quirk { display: grid; grid-template-columns: 22px 1fr; gap: 2px 10px; align-items: start; }
.quirk input { width: 18px; height: 18px; margin: 3px 0 0; }
.quirk label { font-weight: 600; font-size: 14px; }
.quirk p { grid-column: 2; margin: 0; color: var(--muted); font-size: 13px; }

.foot { padding-bottom: 32px; color: var(--muted); font-size: 13px; }
.foot p { margin: 0; }

@media (max-width: 560px) {
  .editor { height: 380px; }
  .regs, .specials { grid-template-columns: repeat(4, 1fr); font-size: 12px; }
  .regs div, .specials div { padding: 3px 4px; }
  .keypad { max-width: none; }
}